21439198 has 32 divisors (see below), whose sum is σ = 36381312. Its totient is φ = 9391200.

The previous prime is 21439183. The next prime is 21439199. The reversal of 21439198 is 89193412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21439199) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 123840 + ... + 124012.

It is an arithmetic number, because the mean of its divisors is an integer number (1136916).

Almost surely, 2^21439198 is an apocalyptic number.

21439198 is a deficient number, since it is larger than the sum of its proper divisors (14942114).

21439198 is a wasteful number, since it uses less digits than its factorization.

21439198 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 360.

The product of its digits is 15552, while the sum is 37.

The square root of 21439198 is about 4630.2481574965. The cubic root of 21439198 is about 277.8025183416.

The spelling of 21439198 in words is "twenty-one million, four hundred thirty-nine thousand, one hundred ninety-eight".